In general, shoes are used to protect a human's feet, and may be manufactured and be sold in a various shapes and kinds. A Shoe includes an upper for protecting an instep and an ankle, and a shoe sole for protecting a sole of the foot, in which the shoe sole increases the friction for walking and softening the impact from the sole while walking.
To soften the impact transferred from the ground to the sole in the above general shoe, an insert can be inserted inside the shoe, the shoe sole or the heel can be made of high buffering rubber and form sponge, or the shoe sole can include a built-in elastic part like an airbag or a spring.
As above mentioned, in case that a shoe sole is made only of rubber or form sponge or has an elastic member like an airbag or a spring inside, it can just absorb impact but cannot help a natural and effective walking. When walking along a walking path which is approximately shaped of an arc traveling from the heel to the toe, the conventional shoe soles have a problem that they cannot help the walker walk naturally and effectively.
Specially, since many people enjoy a bountiful life and work in 5 days per a week, the population of people who enjoy an outdoor life is steeply increasing. At the same time, many shoe makers are investing much time and effort to develop functional shoes, which can provide an improved wearing sensation, protect one's knee and ankle, and improve one's health only in case of walking with the shoes.
As various functions applicable to the outdoor shoes, there are shoes which are for non-slip, impact absorption, air ventilation, preventing athlete's foot, and odor treatment, and are also for round walking which propels one's walking naturally and effectively, as if a sphere rolls on a plane.
Relating to shoe which help the round walking and a walking propelling member therefor, a Korean Patent No. 10-560367 filed on Dec. 9, 2005 and registered on Mar. 7, 2006, discloses a walking propelling member and shoes having the walking propelling member built-in.
The conventional walking propelling member as above mentioned, includes an upper body and a lower body both shaped of a shoe heel, in which a wall member is formed between the upper and lower bodies. The wall member has a central wall vertically standing at the point of about ⅗˜⅘ of the upper/lower bodies, and a first and a second pressing walls a tilt inclined, which are getting more and more inclined from the central wall to both side ends until 16˜20 degrees.
Therefore, when a determined pressure is applied through the conventional walking propelling member, the pressure ratio is high at one end of the walking propelling member, is getting lower as moving to a center of the waling propelling member and getting higher as moving from the center to the other end, wherein the walking propelling member gets curved in a shape of an arc.
In a case that the above conventional walking propelling member is built in the heel portion of the shoe sole or installed as a shoe heel, it can be pressed into a curved shape for round walking by loads of a body applied successively, so as to absorb walking impact, protect the joints of the knee and the ankle, and reduce fatigue on the sole, through natural and effective walking.
But, since the conventional walking propelling member is positioned at the heel of the shoe sole, a short round walking is performed at the first time when the heel touches the ground, however no further round walking follows during the period of walking from the medial arch of foot to the toe.
Accordingly, there are problems that the conventional shoe sole cannot protect the walker's knee and ankle and reduce fatigue of the foot sole, with failure to more reasonable and effective load dispersion and round walking over the whole of the foot sole. Although some of the conventional shoe soles may have an additional built-in walking propelling member, such as airbag or spring, the costs for manufacturing the shoe may increase due to the inconvenience of shoe producing.